Method of forming sheet-metal tanks.



0. J. GROEHN.

METHOD OF FORMING SHEET METAL TANKS.

APPLlCATlON FILED APR.20. I914.

Patent-ed Nov. 16, 1915 v I nvVE/vm Ofta I). Grad??? WITNESSES I BY W4 712mm M 1 W ATTORNEYS Parana OTTO J. GROEHN, OF DETRGI'I, MICHIGAN, ASSIGNOR T0 BRISCOE IEANUFACTUBING COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

METHOD OF FORMING- SHEET-METAL TANKS.

Specification of Letters Patent.

Application filed. April 20, 1914. Serial No. 833,265.

To all whom it may concern:

Be it known that I, Or'ro J. GROEHN, a citizen of the United States of America, re

method of construction particularly the sealing of the joint between the body and the heads of the tank.

In the drawings :Figure 1 is a plan view of a blank for forming the body of thetank, showing the beaded edges thereof; Fig. 2 is a similar View of one of the heads of the tank; Fig. 3 is a cross section showing the manner of first engaging the head with the body; Fig. 4c shows the operation of crimping or securing the head to the body; Fig. 5 illustrates the manner of sealing or soldering the joint; Fig. 6 is a sectional perspective view of the completed joint; and Fig. 7 is a similar view of a modified construction.

In the formation of sheet metal tanks, it is usual to join the heads with the bodies by a lock-seam which is afterward soldered to form a gas or liquid proof seal. The seaming of the parts requires a number of operations, and furthermore places a severe strain upon the metal by the sharp bends required. With my improved method the cost of manufacture may be greatly reduced by dispensing with the usual lock-seam and substituting therefor a crimped bead engagement which is soldered to form the seal. A further saving is effected by forming the beads initially by a die operation and at the same time the blank is fashioned in contour. Thus all of the usual operations required in heading and forming the lock seam are dispensed with, and the blanks as delivered from. the press are quickly assembled, interlocked and soldered, {forming a stronger constructionthan that usually obtained.

head is formed with a which fits within the body of the tank and As shown in Fig. 1, A is a body blank designed Ior use in connection w1th an. ob-

Patented N0'V.'li@, i915.

liquely-inclined head, and therefore fash ioned with the inclined portions B at one edge thereof. This blank may be fashioned upon a press by a die operation, and at the same time the marginal edges thereof may be formed with rounded beads C. The heads I) are formed in a similar manner and are provided with rounded beads E. lhe beads C- and E are so fashioned as to be capable of telescopically engaging, while the overlaps the bead C on the edge of said body. The outer flange F of the bead E is slightly flaring so asto be easily teiescoped with the bead C and is of a size to extend beyond the round of said bead.

When the blanks are formed, the body blank A is bent into the tubular form, having its ends seamed together in the usual way, after which the heads may be engaged therewith, as shown in Fig. 3. lVhen in place the flaring flange F is subjected to a crimping operation which bends it down, as. shown in Fig. 4:, extending inward around the bead C so as to lock the head from disengagement. As the joint between the beads is outside of the tank it may be readily soldered, asv shown in Fig. 5, so as toform a liquid and gas proof seal.

A' joint constructed as described will be stronger than a lockseam sheet metal joint,

as the metal has not been over-strained and any internal pressure in the tank will tend to force the beads together rather than to spring them apart. Where it is desirable that the diameter of the head should not exceed that of the body, a reverse bent bead G may be formed intermediate the bead C and the body portion of the metal, as shown in Fig. 7. This will contribute an additional element of strength without any detrimental stressing oi the metal in bending. v

What I claim as my invention is I The method of forming sheet metal tanks,

' comprising die fashioning-body and head blanks with rounded beaded edges ho that the groove of one blankis adapted toreceive depressed panel F" themoundefiend of the bead of the other In testimony whereof I aifix my signature blank, the latter being provided with a re in presence of twowitnessesw verse bent bead forming a groove telescopi- 7 rm 7 Cally engaging said blanks, crix'hping' the Q GEOEHN' 5 'edge'of the first-mentioned blank into the Wltnessesz groove of the other blank, and solderingthe ARTHUR FLROHRBACH, edjacent'crimped edges to seal the joint. HARRY LUMEKIN. 

